Lubricant compositions



United States Patent LUBRICANT COMPOSITIONS Eugene E. Richardson,Hammond, Ind., assignor to itaudard Oil Company, Chicago, 111., acorporation of diana No Drawing. Application October 18, 1955 Serial No.541,307

7 Claims. (Cl. 252-321) This invention pertains to improved lubricantcompositions and more particularly pertains to internal combustionengine lubricant compositions which inhibit cam follower pitting and/orwear and which inhibit the sticking of hydraulic valve-lifters.

Many modern automobile engines are designed with hydraulic valve-liftersfor smoother and more efficient engine operation. In the operation ofhydraulic valvelifters, the lifters ride on the cam shaft converting therotary motion of the cam into a reciprocating motion, which in turnopens and closes the valves. The bottom of the valve-lifter is known asthe cam follower. The hydraulic part of the valve-lifter functions bymeans of a plunger on the inside of the valve lifter barrel, togetherwith a ball-check and a spring. To obtain higher efiiciency and greaterhorsepower, larger valves, high valve spring pressures and camshaftswhich produce more rapid valve opening and closing are employed. In theoperation of such engines, greatly increased pressures are encounteredwhere the camshaft lobes come into contact with the faces of thevalve-lifters resulting in excessive and severe cam and lifter wear aswell as pitting of the cam followers. This wear and/or pitting cannot beadequately inhibited by most present-day internal combustion enginecrank case lubricants. Surprisingly, the type of anti-wear propertieswhich will inhibit piston ring and/ or cylinder wear are not necessarilythe same as the anti-wear properties necessary to prevent cam and lifterwear and/or pitting; hence many lubricants which are effective ininhibiting ring and cylinder wear are ineffective in preventing cam andlifter wear. A further complicating factor in this problem is caused bythe materials used in making the camshaft and valve-lifters sincedifferent metals and metal combinations are used for this purpose in thevarious engines. Furthermore, because of the small clearances betweenthe plunger and the barrel of hydraulic valvelifters, extremely smallamounts of deposits such as varnish and/or rusting may cause sticking ofthe valve-lifter. Hence, it is essential for good engine operation toprovide a lubricant which will, in addition to inhibit wear and/orpitting, also inhibit the formation of varnish and/or rusting in thevalve-lifter.

As the compression ratio of automobile engines has been increased, theproblem of deposit formation on the backs of intake valves hasincreased. Larger amounts of sticky deposits form and cause valvesticking and power loss. In extreme cases valve burning is caused. Theproblem of reducing or eliminating these deposits has been particularlyvexatious.

It is an object of this invention to provide a lubricant compositionwhich will be substantially free of any tendency to cause valve liftersticking and/or rusting and which will have improved cam followeranti-pitting and anti-wear properties. Another object is to provide alubricant for internal combustion engines which is improved with respectto oxidation stability, detergency, and dispersant powers. An additionalobject is to provide a lubricant composition which has a substantiallylessened tendency to form intake valve deposits. A further object ofthis invention is to provide a method of reducing or eliminating thesticking and/or rusting of hydraulic valve lifters, the pitting and/orwear of cam followers, the corrosion of bearings, and the formation ofintake valve deposits in internal combustion engines. Other objects andadvantages will become apparent from the following description thereof.

In accordance with the herein described invention, the above objects canbe attained by incorporating in a viscous oil, i.e. an oil having aSaybolt Universal viscosity above about seconds at F. and containingbetween about 0.002 and 10% of a neutralized phosphorusandsulfur-containing detergent-type lubricating oil additive, between about0.001 and 5% of the polymerization products of unsaturated fatty acids,and between about 0.001 and 5% of an oil-soluble phenol. The detergentadditive may be one such as an alkaline earth metal, e.g. barium,neutralized reaction product of a phosphorus sulfide and a hydrocarbonsuch as butylene polymers. The polymerization products of theunsaturated fatty acids, for example linoleic acid, have a molecularweight between about 400 and 2000. The oil-soluble phenol may containone or more aromatic nuclei and they may contain one or more hydroxylgroups. The preferred phenols are alkylated monohydric phenols. Aviscosity index improver such as a polybutylene VI improver, ispreferably contained in the lubricating oil composition in an amountbetween about 1 and 20%. Detergent-type additives have been employed inlubricating oils in order to inhibit the formation of sludge and/orvarnish-like products which are deposited in the engine and/or about thevalves and rings of the engine. When lubricating oil compositions havinga neutralized phosphorusand sulfur-containing detergent-type additiveare used for lubricating internal combustion engines having hydraulicvalve lifters, there results excessive pitting and/or Wear of the camfollowers and sticking and/or rusting of the valve lifters. This is evenmore pronounced when the detergent additive is one which has excessbasicity. In addition the oxidation stabiilty of the lubricating oil isdiminshed and a greater degree of bearing corrosion occurs. Whereas, oilsoluble phenolic compounds have no beneficial effect in reducing pittingand/or wear of the cam followers and the polymerization products of theunsaturated fatty acids improve but do not eliminate this problem, ithas been discovered to my surprise that the use of both additivestogether in the oil prevents pitting and/or rusting of the camfollowers. At the same time the formation of intake valve deposits(which are believed caused in part by the large amount of viscosityindex improver required in multi-branded oils) is reduced at least to aharmless level.

The detergent-type lubricating oil additive used is a neutralizedphosphorusand sulfur-containing additive. These additives are usuallyused in amounts of from about 0.002 to about 10%, and preferably fromabout 0.01% to about 5%. Among the phosphorusand sulfur-containingaddition agents are the neutralized reaction products of a phosphorussulfide and a hydrocarbon, an alcohol, a ketone, an amine or an ester.Of the phosphorus sulfide reaction product additives, the neutralizedreaction products of a phosphorus sulfide such as a phosphoruspentasulfide, and a hydrocarbon (note US. 2,316,082) are preferred.

The preferred hydrocarbon used for reaction with the phosphorus sulfideis a mono-olefin hydrocarbon polymer resulting from the polymerizationof low molecular weight mono-olefin hydrocarbons, such as propylene,butylenes, amylenes or copolymers thereof. Such polymers may be obtainedby the polymerization of monoolefins of less than 6 carbon atoms in thepresence of a catalyst, such as sulfuric acid, phosphoric acid, boronfluoride, aluminum chloride or other similar halide catalysts of theFriedel-Crafts type.

The polymers employed are preferably mono-olefin polymers or mixtures ofmono-olefin polymers and isomono-olefin polymers having molecularweights ranging from about 150 to about 50,000 or more, and preferablyfrom about 500 to about 10,000. Such polymers can be obtained, forexample, by the polymerization in the liquid phase of a hydrocarbonmixture containing monoand isomono-olefins, such as butylene andisobutylene at a temperature of from about --80" F. to about 100 F. inthe presence of a metal halide catalyst of the Friedel- Crafts type,such as for example, boron fluoride, aluminum chloride, and the like. Inthe preparation of these polymers, a hydrocarbon mixture containingisobutylene, butylenes and butanes recovered from petroleum gases,especially those gases produced in the cracking of petroleum oils in themanufacture of gasoline can be used.

Parafiinic hydrocarbons such as bright stock residuums,

lubricating oil distillates, waxes, and the like can be reacted withphosphorus sulfide. Olefins having 16 to 30 carbon atoms or higher maybe reacted with the phosphorus sulfide. Other hydrocarbons that can bereacted with a phosphorus sulfide are aromatic hydrocarbons such asbenzene, naphthalene, diphenyl, alkylated aromatic hydrocarbons such asbenzene having alkyl substituents containing preferably at least 8carbon atoms and the like.

' The phosphorus sulfide-hydrocarbon reaction product can be readilyobtained by reacting a phosphorus sulfide, for example P 8 with thehydrocarbon at a temperature of from about 200 F. to about 500 F., andpreferably from about 200 F. to about 400 F., using from about 1% toabout 50%, and preferably from about 5% to about 25% of the phosphorussulfide in the reaction. It is advantageous to maintain a non-oxidizingatmosphere, such as for example, an atmosphere of nitrogen above thereaction mixture. Usually, it is preferable to use an amount of thephosphorus sulfide that will completely react with the hydrocarbon sothat no further purification becomes necessary; however, an excessamount of phosphorus sulfide can be used and separated from the productby filtration or by dilution with a hydrocarbon solvent, such as hexane,filtering and subsequently removing the solvent by suitable means, suchas by distillation. If desired, the reaction product can be furthertreated with steam at an elevated temperature of from about 100 F. toabout 600 F.

The phosphorus sulfide-hydrocarbon reaction product normally shows atitratable acidity which is neutralized by treatment with a basicreagent. The term neutralized reaction product product of a phosphorussulfide and a hydrocarbon as used herein means a phosphorussulfidehydrocarbon reaction product having at least 1% of its titratableacidity neutralized by the reaction with a basic reagent. The phosphorussulfide-hydrocarbon reaction product when neutralized with a basicreagent containing a metal constituent is characterized by the presenceor retention of the metal constituent of the basic reagent. The termalso includes those products which contain the metal constituent inexcess of the amount stoichiometrically necessary to replace the acidichydrogen atoms contained in the phosphorus sulfide-hydrocarbon reactionproduct. Such compounds are known in the art as having excess basicity"or as having an alkaline reser e Prior to neutralization the reactioProd can 4 be hydrolyzed and clayed to remove inorganic acids ofphosphorus as described in U.S. 2,688,612 issued to R. W. Watson,September 7, 1954.

The neutralized phosphorus-sulfide-hydrocarbon reaction product can beobtained by treating the acidic reaction product with a suitable basiccompound, such as hydroxide, carbonate, oxide, or sulfide of an alkal oralkaline earth metal, such as for example, potass um hydroxide, sodiumhydroxide, sodium sulfide, calcium oxide, lime, barium hydroxide, bariumoxide, etc. The neutralization of the phosphorus sulfide-hydrocarbonreaction product is carried out preferably in a non-oxidizing atmosphereby contacting the acidic reaction product either as such or dissolved ina suitable solvent, such as naptha with a solution of the basic agent.As an alternative method the reaction product can be treated with solidalkaline compounds such as KOH, NaOH, Na CO CaO, BaO, Ba(OH) Na- S, andthe like, at an elevated temperature of from about F. to about 600 F.Neutralized reaction products containing a heavy metal constituent, suchas for example, tin, titanium, aluminum, chromium, cobalt, zinc, iron,and the like, can be obtained by reacting a salt of the desired heavymetal with the phosphorus sulfide-hydrocarbon reaction product which hasbeen treated with a basic reagent such as above-described.

The unsaturated fatty acids which may be polymerized are those naturalor synthetic mono-carboxylic acids which generally will have two or moreunsaturated linkages. If natural fatty acids are employed they willusually have 16 to 26 carbon atoms, most frequently 18 carbon atoms, butif synthetic unsaturated fatty acids are used they may have a lesser orgreater number of carbon atoms. Examples of the natural fatty acids arethose such as linoleic, linolenic, ricinoleic (which upon heating formslinoleic acid), linoleaidic, elaidolinolenic, eleostearic, arachidonic,eicosatrienaic, cetoleic, docosatrienoic and the like. The free fattyacids can be polymerized eitherthermally or with the assistance ofcatalysts. A method of thermally polymerizing free fatty acids (see U.S.2,482,761) consists of hydrolyzing a fat or an oil, adding a smallportion of water, and heating in a pressure vessel until substantiallyall of the diand tri-unsaturated fatty acids present polymerize. Theresultant product is then heated at a reduced pressure to distill offvaporizable constituents, leaving behind the polymerized unsaturatedfatty acids. The polymerization reaction is carried out at a temperatureof about 300 to 360 C. for about three to eight hours at a pressurevarying between 75 and 500 p.s.i.g. The polymerization product mayconsist of monomers, dimers, trimers, and higher polymers of theunsaturated fatty acids. The various fats or oils which may behydrolyzed to produce the free ,fatty acids used in the above thermalpolymerization are those such as sardine oil, linseed oil, soybean oil,castor oil, peanut oil, palm oil, olive oil, cottonseed oil, sunflowerseed oil, and the like.

Another method of preparing the polymerized fatty acids consists ofsubjecting fats and oils such as have been listed supra (withoutprevious hydrolysis) to a thermal or catalytic polymerization to causepolymerization of the esters of the unsaturated carboxylic acids to thedimers, trimers, and higher polymerization products thereof,-

followed by hydrolysis to yield the corresponding polymers of the acids.A large source of the polymerized unsaturated fatty acids are thoseresidual acids obtained by methanolysis (see U.S. 2,450,940) of thesemi-drying or drying type oils such as castor oil, soybean oil, andothers listed supra, polymerizing the methyl esters, removingunpolymerized compounds, saponifying the residual esters and freeingpolymerized acids therefrom. The products of catalytic polymerization ofsemi-drying oils such as the BF polymerization products of soybean oil,cottonseed oil, or the like also produce polymers suitable for use inthe invention.

It should be understood that while various polymerized unsaturated fattyacids may be used, theydo not all provide the same effect, and indeedthere may be pronounced dilferences when used in the composition of thisinvention. A highly preferred source of the polymerized unsaturatedfatty acids is obtained as a by-product still residue in the manufactureof sebacic acid by the dry distillation of castor oil in the presence ofsodium hydroxide. A method of obtaining such by-product still residuesin the manufac-' ture of sebacic acid is described in U.S. 2,470,849,issued to W. E. Hanson May 24, 1949. The mixture of high molecularweight unsaturated'fatty'acids comprises monomers, dimers, trimers, andhigher polymers in the ratio of from about 45% to about 55% of amonomers and dimers fraction having a molecular weight in the range offrom about 300 to 600, and from about 45% to about 55% of a trimers andhigher polymer fraction having a molecular weight in excess of 600. Thefatty acid polymers result in part from athermal polymerization of fattyacid type constituents of the caster oil, and in part from otherreactions, such as the inter-molecular esterification, of such acid toform high molecular weight products. The acid mixture, which is mainly amixture of polymeric long chain polybasic carboxylic acids, is furthercharacterized by the following specifications:

Acid No.150 to 164. Saponification No.-175 to 186. Free Fatty Acids--75to 82% Iodine Value-44 to 55. Non-saponifiables2.5 to 5% A fatty acidmixture such as above described is marketed under the trade name D-50Acids, and also as VR-l Acids.

The polymerization products of the unsaturated fatty acids may have amolecular weight between about 400 and 2000. Those polymers having amolecular weight higher than about 500, and especially those havingmolecular weights averaging about 800 or higher are particularlypreferred for use in this invention. The polymerization products mayconsist primarily of dimers and trimers of linoleic acid, for exampleEmery 955 Dimer Acid which contains 85% f the dimer, 12% of the trimer,and 3% of the monomer of linoleic acid may be used. Especially preferredpolymerized unsaturated acids are the polymerization products of acidssuch as linoleic acid having a molecular weight between about 400 and2000, wherein the polymerization products consist of more than about 40%of the trimer and higher molecular weight polymers of linoleic acid withthe remainder consisting primarily of monomers and dimers of linoleicacid.

The polymerization products of the unsaturated fatty acids should beused in an amount between about 0.001 and 5.0% in the oil, preferablybetween about 0.05 and 2.0%,, for example about 0.2%. The amount ofpolymerized fatty acids, as well as the amount of phenolic compoundused, may be varied depending upon the oil in which it is employed, thematerials used in making the camshaft and valve-lifters, the valvespring pressures and other factors which affect the degree of pittingand wear.

The oil-soluble phenol is employed in an amount between about 0.001 and5%, preferably between about 0.05 to 2%. The phenol may have one or morehydroxyl groups attached to an aromatic nucleus. The automatic nucleusmay consist of one, twoor three rings. The preferred phenols arealkylated monohydric phenols suchas cresols, xylenols, mesitols,2,6-di-tert-butyl p-cresol, 2,4, tS-tri-tert-butyl phenol,2,4-dimethyl-6-tert octyl phenol, amyl phenols, thymol, cyclohexylphenol, nonyl phenol, phenols alkylated with olefin polymers such aspolypropylene, polybutylene, etc., which have from 6 to 24 carbon atomsin the polymer, wax-substituted phenols and the like. Also included inthis definition of alkylated monohydric phenols are the alkylene bisphenols such as methylene diphenol, methylene bis p-octyl phenol andsimilar compounds. Phenol itself, as well as the various naphthols, andanthranols may be used if desired. Dihydric and trihydric phenols suchas catechol, tertbutyl catechol, pyrogallol, phloroglucinol, are quiteeffective.

Phenols which contain sulfur in the molecule should not be used. It hasbeen found that such compounds do not provide the beneficial effect ofthe phenols which are free of sulfur in the molecule. Certain of thesulfurcontaining phenols such as thiocresols have an aggravating effecton the problem of pitting and/or wear of the cam followers.

Any of a number of different viscosity index improvers may be used inthe lubricating oil composition. For example, polymers of butylenes,e.g. polyisobutylene which is sold commercially as Paratone, may beused. Acrylic acid esters such as the commercially available Acryloidsmay be employed. Polymers of isobutylene such as, Paratone, arepreferred and are very efiective for reducing the change in viscosity ofthe oil with change in temperature. The amount of viscosity indeximprover, of course, depends upon the improvement in viscosity indexwhich is desired and the efiectiveness of the particular viscosity indeximprover. Generally between about 1 and 20% of the viscosity indeximprover is employed in the lubricating oil composition.

The phosphorusand sulfur-containing detergent-type additive, thepolymerization products of unsaturated fatty acids and the oil-solublephenol can be added individually to the lubricating oil base or they canbe pre-mixed (preferably together with the viscosity index improver) inthe desired proportions and the resultant mixture then added to thelubricating oil base. Concentrations of a suitable oil base containingmore than 10%, for example up to 50%, of the detergent-type additive,with more than about 5%, for example up to 25%, of the polymerizationproducts of the unsaturated fatty acids, and more than about 5%, forexample up to 25%, of the phenol can be used for blending with thehydrocarbon oils in the proportions desired for the particularconditions of use to provide a finished product containing the desiredamounts of these additives, e.g;, 0.002 to 10% of the detergentadditive, 0.001 to 5% of the polymerized acids and 0.001 to 5% of thephenol. The lubricating oil base may also contain other additives suchas VI improvers, bearing corrosion inhibitors and the like.

A number of performance tests for evaluating the ability of thelubricating oil to inhibit pitting and/or wear as well as its ability toprevent rusting of the hydraulic valve-lifters were made. The tests madeto determine the anti-pitting and anti-wear properties of the oil isknown as the L-S-5 test established by the General Motors ResearchDivision. The test is made on a 1953 Chevrolet Power Glide engineequipped with chilled iron lifters, forged steel cams, steel rocker armshafts, malleable iron rocker arms and operating at 3150 r.p.m. with aload of 30 brake horsepower, an oil sump temperature of 255 F. and awater outlet temperature of 200 F. Dual valve springs are installed togive an assembled static valve spring load of 240 pounds at 0.330 inchvalve opening. The test is continued for 24 hours at the end of whichthe cam followers are inspected for pitting and over-all wear.

The effectiveness of the additives for preventing pitting of the camfollowers is shown in the table which follows. In obtaining the datapresented in this table various additives for preventing pitting and/orwear of the cam followers were added to the oil composition of Sample 1.Sample 1 was composed of the following:

Composition Sample 1.SAE l0W-30 oil 3.3% of a barium-containingneutralized reaction product of P25 and a polybutene of about 1000molecular weight 0.75% of a sulfurized dipentene (35% sulfur) 11% ofParatone 31 ppm. anti-foam agent.

7 L-S- Engine Tests Lifters Amount and Type of Anti-Fitting andAnti-Wear Additive Fitted Sample N o. 3 plus 0.20% p-eresol Sample N o.3 plus 0.20% 2,6 di-t-butyl p-cresol. Sample No. 3 plus 0.20% amylphenol Sample No. 3 plus 0.32% polypropylene phenol' Sample No. 3 plus0.20% t-butyl catechol Sample No. 3 plus 0.50% methylene bis p-octylphenol. Sample No. 3 plus 0.30% nonyl phenol sulfide 3 Sample N o. 3plus 0.20% thiooresols 7 1 Molecular weight of 425.

Sample 1 shows that unless an anti-pitting and antiwear additive ispresent in the oil almost all of the cam follower surfaces will bepitted. Sample 2 shows that the oil-soluble phenol does not impart anyimproved antipitting and anti-wear properties to the oil. Sample 3 showsthat the polymerization products of the unsaturated fatty acids improvethe oil only slightly in the latter respect. However, Samples 4 throughshow that when the oil-soluble phenol and the polymerization products ofthe unsaturated fatty acids are used together in the oil the problem ofpitting and/or wear of the cam fol lowers iseliminated. Samples 11 and12 indicate that the phenol must not contain sulfur in the molecule,Sample 12 pointing out in particular that thiocresols in: crease theproblem of pitting and/or wear.

An additional series of experiments (Automotive Diesel L-5 engine testsand L-4 engine tests) showed that the presence of the oil-soluble phenolin the lubricating oil composition containing the detergent additive andthe polymerization products of the unsaturated fatty acids, improved theoxidation stability of the oil and reduced the bearing corrosion weightloss.

Performance tests which evaluated the ability of the lubricating oil toinhibit the formation of intake valve deposits were made. The tests madewere known as the Cadillac Cold Test. The test is made on a 1954Cadillac engine operating at 2000 rpm. for 100 hours of continuousrunning under conditions of no load and a water temperature of 165 F.Sample 3 of the preceding table as well as Samples 13 and 14 whichcontained added phenols were evaluated in the tests. The results show:

Engine intake valve deposits Amount and Type of Anti-Fitting and 0.Anti'Wear Additive Amount of 7 Deposits None Moderate to Sample No. 3plus 0.35% nonyl phenol Sample No. 3 plus 0.50% 2,6 di-t-butyl pcresoThe above tests show that the presence of the phenol in the lubricatingoil composition inhibits greatly the amount of intake valve depositswhich are formed. In addition the deposits are not of such a hardnature.

While the present invention has been described by the use of ouradditives in petroleum lubricating oils other lubricating oil bases canbe employed. For example oils obtained by the polymerization of olefins,synthetic lubricating oils of the alkylene oxide type, for example, UconOils, and the polycarboxylic acid ester type oils such as theoil-soluble esters of adipic acid, sebacic acid, azelaic acid,'etc., maybe used.

.Unless otherwise stated, the percentages stated herein and in theclaims are weight percentages.

Although the present inventionv has been described with reference tospecific'preferred embodiments thereof, the invention is. not to beconsidered as limited thereto but includes within its scope suchmodifications and variations as come with the spirit of the appendedclaims.

I claim:

1. A, lubricating oil composition comprising a major proportion of amineral lubricating oil base, between about 0.002 and 10% of an alkalineearth-containing neutralized reaction product of a phosphorus sulfideand an' olefin polymer, between about 0.001 and 5% of the polymerizationproducts of unsaturated fatty acids having from 16 to 26 carbon atoms,said polymerization products having a molecular weight between about 400and 2000, and between about 0.001 and 5% of an oil soluble phenolselected from the group consisting of al kylated monohydric phenols andalkylated dihydric phenols.

2. The composition of claim 1 wherein the polymerization products of theunsaturated fatty acids consist of more than about 40% of the trimer andhigher molecular weight polymers, the remainder being essentiallymonomers and dimers of the unsaturated fatty acids.

3. The composition of claim 1 wherein said unsaturated acid is linoleicacid. I

4. The composition of claim 1 which also contains between about 1 and20% of a viscosity index improver.

5. A lubricating oil composition comprising a major proportion of amineral lubricating oil base, between about 0.002 and 10% of aphosphorus sulfide-olefin polymer reaction product which has beenneutralized with a basic barium compound, between about 0.05 and 2% ofthe polymerization products of linoleic acid, said polymerizationproducts having a molecular weight between about 400 and 2000 andconsisting of more than about 40% of the trimer and higher molecularweight polymers of linoleic acid and the remainder being essentiallymonomers and dimers of linoleic acid, and between about 0.05 and 2% ofan oil-soluble alkylated monohydric phenol.

6. The composition of claim 5 which also contains between about 1 and20% of a viscosity index improver.

7. An addition agent for a lubricating oil composition comprising aconcentrated solution of a mineral lubricating oil base containing'morethan about 10% of an alkaline earth-containing neutralized reactionproduct of a phosphorus sulfide and an olefin polymer, more than about5% of the polymerization products of unsaturated fatty acids having from16 to 26 carbon atoms, said polymerization products having a molecularweight between about 400 and 2000, and more than about 5% of anoilsoluble. phenol selected from the group consisting of alkylatedmonohydric phenols and alkylated dihydric phenols, said concentratedsolution being capable of dilutionwith a mineral lubricating oil base toform a homogeneous mixture containing between about 0.002 and 10% of theneutralized phosphorus sulfide-olefin polymer reaction product, betweenabout 0.001 and 5% of the polymerization products of the unsaturatedfatty acids, and between about 0.001 and 5% of the phenol.

References Cited in the file of this patent UNITED'STATES PATENTS2,202,877 Stevens et al. June 4, 1940 2,316,090 Kelso et al. Apr. 6,1943 2,461,961 Buckmann et al. Feb. 15, 1949 2,631,979 McDermott Mar.17, 1953 2,734,032 Coppock Feb. 7, 1956 2,833,713 Lemmon et al. May 6,1958

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF AMINERAL LUBRICATING OIL BASE, BETWEEN ABOUT 0.002 AND 10% OF AN ALKALINEEARTH-CONTAINING NEUTRALIZED REACTION PRODUCT OF A PHOSPHOURS SULFIDEAND AN OLEFIN POLYMER, BETWEEN ABOUT 0.001 AND 5% OF THE POLYMERIZATIONPRODUCTS OF UNSATURATED FATTY ACIDS HAVING FROM 16 TO 26 CARBON ATOMS,SAID POLYMERIZATION PRODUCTS HAVING A MOLECULAR WEIGHT BETWEEN ABOUT 400AND 2000, AND BETWEEN ABOUT 0.001 AND 5% OF AN OIL SOLUBLE PHENOLSELECTED FROM THE GROUP CONSISTING OF ALKYLATED MONOHYDRIC PHENOLS ANDALKYLATED DIHYDRIC PHENOLS.